Finding a bathtub for a tall, fast-growing infant can be challenging, especially as they transition from lying down to sitting up. Many parents find that tubs with removable internal cushions or slings are best, as these inserts become unnecessary once the baby gains enough trunk control to sit independently. Look for spacious, ergonomically designed tubs from reputable brands like R for Rabbit or Star and Daisy, and don't be afraid to skip the internal support if your baby is already reaching the length milestones for their age.